Expanding deep water sound source vehicle

ABSTRACT

1. An expandable deep water sound source comprising: A HOUSING, A FLEXIBLE BAG COLLAPSED AND FOLDED WITHIN SAID HOUSING, A MOTOR, A POWER SOURCE FOR SAID MOTOR, A PUMP DRIVEN BY SAID MOTOR AND CONNECTED TO SAID BAG FOR FILLING SAID BAG WITH THE SURROUNDING MEDIUM, AN EXPLOSIVE CORD WRAPPED IN A HELIX ABOUT SAID BAG TO FORM A HELICAL CHARGE WHEN SAID BAG HAS BEEN FILLED AND THEREBY EXPANDED TO A SUBSTANTIALLY CYLINDRICAL-SHAPED CONFIGURATION, MEANS FOR RELEASING THE BAG FROM SAID HOUSING AND FOR STARTING SAID MOTOR AFTER THE HOUSING HAS REACHED A PRESET DEPTH, MEANS CONNECTING THE BAG AND THE POWER SOURCE, WHEREBY THE POWER SOURCE MAY ACT AS A BALANCE WEIGHT FOR SUPPORTING THE EXPANDED BAG IN A HORIZONTAL POSITION AS THE BAG AND POWER SOURCE CONTINUE TO SINK IN THE WATER, AND MEANS FOR DETONATING THE EXPLOSIVE CORD AT A PREDETERMINED DEPTH.

United States Patent Vass [4 Dec. 19,1972

[54] EXPANDING DEEP WATER SOUND SOURCE VEHICLE [72] Inventor: Oscar R. Vase, Adelphi, Md.

[73] Assignee: The United States oi America as represented by the Secretary of the Navy 221 Filed: Aug. 311, 11964 [21 Appl. No.: 393,269

[56] References Cited UNITED STATES PATENTS Beckwith, Jr ..l02/l6 *Primary Examiner-Richard A. Farley AttorneyJ. P. Dunlavey and J. O. Tresansky EXEMPLARY CLAIM 1. An expandable deep water sound source comprising:

a housing,

a flexible bag collapsed and folded within said housing,

a motor,

a power source for said motor,

a pump driven by said motor and connected to said bag for filling said bag with the surrounding medium, W ,7 V 7 an explosive cord wrapped in a helix about said bag to form a helical charge when said bag has been filled and thereby expanded to a substantially cylindrical-shaped configuration,

means for releasing the bag from said housing and for starting said motor after the housing has reached a preset depth,

means connecting the bag and the power source, whereby the power source may act as a balance weight for supporting the expanded bag in a horizontal position as the bag and power source continue to sink in the water,

and means for detonating the explosive cord at a predetermined depth.

8 Claims, 5 Drawing Figures PATENTED Bin 19 I972 SHEET 1 BF 3 Oscar R. Vass mvsmon PATENTED I97? 3. 706. 964

sum 2 0F 3 Oscar R. Vass INVENTOR.

ATTORNEY NSFNT 4 G I F FIG. 3

PATENTEDDEBIQ 1912 3,706,964

Pressure Switches Retaining Ring Release Actuator "1 Hydrostatic Pressure Responsive EXPANDHNG DEEP WATER SOUND SOURCE VEHICLE The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates generally to underwater sound producing devices and more particularly to an expanding deep water sound source vehicle for producing an underwater explosion at a predetermined depth.

In modern day warfare explosive echo ranging charges or underwater sound producing devices have been used to enable airborne personnel to detect the presence of enemy submarines which are beneath the surface of the water. These devices which contain small amounts of explosive TNT are dropped into the water from an aircraft and are exploded at a predetermined depth to emit compressional waves which are transmitted through the water. These compressional or sound waves are propagated through the water to a submarine and bounced back to a detecting means located on the surface of the water. The detecting apparatus emits radio signals that are received by the aircraft which dropped the charge into the water, thus giving an indication of the location of the submarine.

Helical charges have been found to be useful asunderwater sound sources for this purpose because of their ability to provide an accurately pulsed source of sound. Therefore, in the preferred form of a sound producing device embodying this invention, a casing containing a flexible bag is airdropped into the water where the casing and the bag are separated and the bag is filled with the surrounding medium of water and thereby expanded so as to provide at a given depth a closed, sausage-shaped bag which is wrapped with an explosive cord to form a helical charge. After deploying, a balance weight causes the expanded bag to sink with the bag in a horizontal position so that when the design depth is reached the helical charge may be detonated by a firing device to provide a sound pulse while sinking in a horizontal position.

Accordingly, it is an object of this invention to provide a supporting structure and carrying vehicle for a helical charge sound source to be used in deep water.

It is another object of this invention to provide an expanding deep water sound source vehicle for creating an underwater explosion to produce a sound pulse.

Still another object of this invention is to provide a new and improved apparatus for producing an underwater explosion at a predetermined depth.

Yet another object of this invention is to provide a helical-charge sound source to be used in deep water for creating an underwater explosion to produce a sound pulse.

The exact nature of this invention as well as other objects and advantages thereof will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:

FIG. l is a longitudinal elevation view with portions broken away of an underwater sound producing device in accordance with this invention and shown in its initial package;

FIG. 2 is a diagrammatic view illustrating the sound producing device of FIG. ll after it has been deployed and with the bag indicated as filled from the surrounding medium of water;

FIG. 3 is a partial sectional view of another embodiment of a sound source vehicle formed in accordance with this invention and shown in its initial package;

FIG. 4 is a view illustrating the sound producing device of FIG. 3 after it has been deployed and with the bag in its expanded condition; and

FIG. 5 is a diagrammatic view illustrating a hydrostatic pressure responsive switch and associated control circuit for controlled energization of the several electro responsive devices incorporated in the sound source vehicle. H V 7 Referring now to FIGS. 1 and 2 the initial package of the sound source vehicle is shown to include a con tainer for the sound producing device comprising a forward casing 11 and an after casing 12 connected together by an explosively releasable coupling band 13. Within the forward casing Ill there is positioned a centrifugal or any non-positive displacement type pump 14 driven by a liquid filled electric motor 15 receiving its power from a battery pack 16, which may be liquid filled so as to be unaffected by pressure. The forward casing 11 may be divided into two separate substructures 11a and 11b, as shown, the former housing the pump 14 and motor 15 and the latter containing the battery pack l6. These substructures may be joined together by a clamp band 17 and provided with means including a conductor 18 for providing electrical connection therebetween during their assembly.

A flexible bag 19, which may be constructed of a neoprene-coated nylon fabric or other lightweight, watertight, nonstretching fabric, is collapsed and folded within the after casing section 12. This bag is so constructed that when inflated or otherwise expanded it assumes a cylindrical or sausage-shaped configuration. At either end thereof there is connected a guy-line 20 loosely positioned within the after casing section 12 and extending from a point connection 21 at the end portion of substructure lllla of casing 111. A pump-up flexible tubing type line 22, shown in FIG. 1 in a collapsed and folded condition, is connected at one end to a center portion of the flexible bag 19 and at the other end to the discharge port of pump id. Wrapped about the bag I? and secured thereto by adhesive bonding is a helix of explosive cord 23 which is adapted to be detonated by a pressure actuated firing device, shown diagrammatically in FIG. 5 which may be any suitable pressure change responsive switch of a character well known in the art, at a predetermined depth.

In operation, the initial package is aircraft-dropped, and upon water entry, sinks rapidly to a preset depth at which a pressure switch or other sensing device, FIG. 5, causes the after casing E2 to be released from the forward casing 11 by explosively releasing the clamping band 13 by use for example of a Primacord ribbon or other suitable explosive charge or charges of a conventional or shaped charge nature as desired which is disposed under the band 13 and connected for actuation by the sequentially actuated switch in a manner indicated by FIG. 5. While sinking to this depth the after casing section 12, with respect to which no measures have been taken to effect sealing thereof, is free-floodl060l l 0757 ing and the pressure inside and outside the bag 1% is equalized due to the free access of water to the bag interior through the pump casing. When the after casing section 12, which may be composed of a split casing or half-shells, is dropped, the folded bag assembly 119 trails behind the falling forward casing section 11 and the pump motor is started by action for example of the aforementioned hydrostatic pressure change actuated switch of FIG. 5. The pressure sealing problem for the pump motor may be solved through the use of a wet motor or the use of an oil-filled case fitted with a bellows or soft patch to equalize external and internal pressure.

The first task of the running pump 14 is to transfer water into the interior of the flexible bag l9 through .a connecting pump-up line 22, causing the bag to expand into its final cylindrical or sausage shape and size. During this period, until the bag is filled to full volume, there is essentially no pressure differential across the wall of the bag and the work of the pump consists only of overcoming the inertia of the water and line friction as necessary to transfer it to the interior of the bag.

The second phase of the pumping operation consists of maintaining a slight pressure differential inside the flexible bag 19 after the bag has been filled to full volume. With a properly designed centrifugal pump, this may be accomplished merely through pump slippage while running at a constant speed. It must be kept in mind that the pump M is required to provide only a slight differential pressure across the wall of the bag 19 regardless of the depth, and thereby the corresponding pressure, of operation in order that the internal pressure thereof may keep the bag rigid and free of wrinkles in its surface while sinking. It has been found that a pressure differential in the range of 2 pounds per square inch or less will be satisfactory.

The forward casing structure if containing the battery pack 16, the motor 15 and the pump 14, when supported beneath the center of the bag W by the pumpup line 22 and the guy-lines or cables 2% attached to the ends of the bag, provides a balance weight to cause the expanded helical charge carrier vehicle 'to sink in a horizontal orientation, as illustrated in MG. 2. At the desired depth the aforedescribed pressure-actuated firing device detonates the explosive cord 23 on one end of the vehicle, thus completing the functioning of the device and causing the desired compressional or sound waves to be propagated through the water.

Referring now to H68. 3 and 4, there is shown another embodiment formed in accordance with the present invention, differing principally from the aforedescribed embodiment illustrated in FIGS. 11 and 2 in the location of the pump and motor elements thereof. In this embodiment, the centrifugal pump M and the motor 15 are mounted in one end of the flexible bag 19 and connected to the battery pack 16 in the balance weight casing structure U. by means of an electrical cable 18a in one of the support lines 2G9.

it may be seen in this embodiment that the after portion of the casing section 111 is provided with a chamber 24 for housing the electrical cable 38a in the initial package. An explosively releasable clamping band E3 connects the forward casing Ill and the after casing B2 in the same manner as hereinbefore described. The operational sequence of the two embodiments of the expanding deep water sound source vehicle is the same in either case. Both embodiments are packaged in the same size initial package and provide the same size and shape of cylindrical structure after deployment. Both utilize the battery pack and its heavy outer casing as the balance weight to provide for horizontal sinking.

The advantage of locating the pump and the motor in the end of the bag is that it is not necessary to pump through a line to the bag. However, on the other hand, locating the pump and the motor in the forward casing with the batteries has certain attendant advantages. For example, the weight of the pump and the motor can be used as part of the balance weight, there is not weight unbalance on the bag, no lengthy electrical connection necessary between the battery case and the flexible bag for pumping purposes, and simpler packaging is possible having increased resistance to shock. Moreover, the absence of the extra weight of the pump and the motor in the one end of the bag would probably make deployment thereof easier, the bag then being free to act as a drag chute which will pull away from the forward case when the after case has opened.

it should be readily apparent therefore that a new and improved underwater sound producing device has been provided which is operable at any depth of operation, which makes use of the surrounding medium as a filler and expanding means for the structure thereby allowing the initial packaging in a minimum space, and which accomplishes expansion of the structure to its final shape without the use of complex mechanical gear.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. it is therefore to be understood, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. An expandable deep water sound source comprising:

a housing,

a flexible bag collapsed and folded within said hous- 7 ing,

a motor,

a power source for said motor,

a pump driven by said motor and connected to said bag for filling said bag with the surrounding medium,

an explosive cord wrapped in a helix about said bag to form a helical charge when said bag has been filled and thereby expanded to a substantially cylindrical-shaped configuration,

means for releasing the bag from said housing and for starting said motor after the housing has reached a preset depth,

means connecting the bag and the power source, whereby the power source may act as a balance weight for supporting the expanded bag in a horizontal position as the bag and power source continue to sink in the water,

and means for detonating the explosive cord at a predetermined depth.

2. An expandable deep water sound source in accordance with claim it wherein said housing is composed of a split casing structure separable into forward and after sections thereof,

lOGOll 0758 said flexible bag being initially positioned within one of said sections,

said motor, pump and power source being positioned within the other of said sections,

and said means for releasing the bag from the housing includes means for separating the forward and after sections of the housing.

3. An expandable deep water sound source in accordance with claim ll wherein said housing is composed of a split casing structure separable into forward and after sections thereof,

said flexible bag being initially positioned within one of said sections,

said motor and said pump being positioned within said flexible bag,

said power source being positioned within the other of said sections,

and said means for releasing the bag from the housing includes means for separating the forward and after sections of the housing.

4. The device according to claim 1 wherein said flexible bag is composed of a neoprene-coated nylon fabric.

5. The device according to claim 1 wherein said pump is a non-positive displacement type pump.

6. A device according to claim 3 wherein said means connecting the bag and the power source includes an underwater electrical cable.

7. An expandable deep water sound source comprismg:

a collapsed flexible bag composed of a lightweight,

watertight and nonstretching fabric,

means for filling said bag with the surrounding median explosive cord wrapped in a helix about said bag so as to form a helical charge when said bag has been filed and thereby expanded to a substantially cylindrical-shaped configuration,

means for actuating the bag filling means when the bag is submergedto a preset depth,

and means for detonating the explosive cord at a predetermined depth greater than said preset depth.

8. A device according to claim 7, further provided with means for supporting the expanded flexible bag in a horizontal position as it sinks in the water to said predetermined depth.

l060ll 0759 

1. An expandable deep water sound source comprising: a housing, a flexible bag collapsed and folded within said housing, a motor, a power source for said motor, a pump driven by said motor and connected to said bag for filling said bag with the surrounding medium, an explosive cord wrapped in a helix about said bag to form a helical charge when said bag has been filled and thereby expanded to a substantially cylindrical-shaped configuration, means for releasing the bag from said housing and for starting said motor after the housing has reached a preset depth, means connecting the bag and the power source, whereby the power source may act as a balance weight for supporting the expanded bag in a horizontal position as the bag and power source continue to sink in the water, and means for detonating the explosive cord at a predetermined depth.
 2. An expandable deep water sound source in accordance with claim 1 wherein said housing is composed of a split casing structure separable into forward and after sections thereof, said flexible bag being initially positioned within one of said sections, said motor, pump and power source being positioned within the other of said sections, and said means for releasing the bag from the housing includes means for separating the forward and after sections of the housing.
 3. An expandable deep water sound source in accordance with claim 1 wherein said housing is composed of a split casing structure separable into forward and after sections thereof, said flexible bag being initially positioned within one of said sections, said motor and said pump being positioned within said flexible bag, said power source being positioned within the other of said sections, and said means for releasing the bag from the housing includes means for separating the forward and after sections of the housing.
 4. The device according to claim 1 wherein said flexible bag is composed of a neoprene-coated nylon fabric.
 5. The device according to claim 1 wherein said pump is a non-positive displacement type pump.
 6. A device according to claim 3 wherein said means connecting the bag and the power source includes an underwater electrical cable.
 7. An expandable deep water sound source comprising: a collapsed flexible bag composed of a lightweight, watertight and nonstretching fabric, means for filling said bag with the surrounding medium, an explosive cord wrapped in a helix about said bag so as to form a helical charge when said bag has been filed and thereby expanded to a substantially cylindrical-shaped configuration, means for acTuating the bag filling means when the bag is submerged to a preset depth, and means for detonating the explosive cord at a predetermined depth greater than said preset depth.
 8. A device according to claim 7, further provided with means for supporting the expanded flexible bag in a horizontal position as it sinks in the water to said predetermined depth. 